Carriage-returning mechanism for typewriting machines



- Dec. 28 1926. 1,612,069

A. J. SMITH cmmmes RETURNING MECHANISM FOR TYPEWRITVING MACHINES Filed Sept; 22, 1924 I nu U u 6 I Q 0 O y d O 0 d Patented Dec. 28, 1926.

, UNETEE STATS v ALE; AMBER JOHN SMITH, OF BOUBNEMOUTH, ENGLAND.

CARRIAGE-RETURNING MTECHANISM L CR TYPEKVRITING IKEACHINES.

Application filed September 22, N24, Serial No.

This invention relates to typewriting machines in which in order to effect the return of the carriage Without the necessity 'for manual effort applied thereto, there is provided in conjunction with the usual spring employed for propelling the carriage in letter spacing a second spring of greater strength which is adapted to be wound up by depression of the usual key levers in operating the machine and is adapted to be set free to return the carriage upon depression or release of a key or the like provided for this purpose.

The object of the present invention is to provide an improved mechanism which is more simple, compact, and readily adaptable to existing machines than those hitherto devised.

The spring mechanism of the invention may be contrived to effect the return of the carriage to the beginning end of the line or to any given position, dependent, say, on the selection of one of several release keys, or determinable by adjustment devices, such as the tabular keys employed in the ordinary typeWriting machines. These devices could be arranged in the carriage run-way, or on the face or periphery of one or the other of the spring drums, to come into operation simultaneously with the release of the one drum.

The invention is illustrated diagrammat ically in the accompanying drawing which shows certain parts of the improved carriage returning mechanism; Figs. 1 and 2 showing the mechanism in different positions, while Fig. 3 is a detail view of worm gear ing operating the carriage returning mechae nism.

Referring to the drawing, a indicates the usual propelling spring drum of a typewriter with its coil spring a and adjusting bush a mounted on the usual spindle a.

The drum (.1, is connected with the carriage in any suitable manner which will cause it to move either forwards or backwards in accordance with the direction in which the drum or rotates; for example by a pair of steel ribbons, or webs, connected one with each end of the carriage and wound in reverse directions on the drum (1, one of said ribbons or webs passing round a pulley located beyond the end of the carriage.

In Figure 2 of the drawings 00 is the ordinary tension band, which is being coiled on drum e tor rather is .iuliy coiled, as the 739,071, and in Great Britain October 2, 192B.

turn of the two drums is about to commence, they being 111 gear) and y is the tension band or web for returning the carriage to its starting position again. In the position shown, a: is all-in and y all-out. Band would be fixed to the ordinary point on the carriage and 3 also attached to the carriage, but running over a jockey-pulley at the far side 01 the machine, arranged for pulling the carriage back. On the same spindle is disposed in juxtaposed relation with the drum or on an adjusting bush 6 a return spring drum 6 embracing a coil spring Z) of greater strength than the spring a said drum 6 being formed integral with a worm wheel 6 engaged by a worm w having at one end ratchet teeth 0 engaged by a pawl 0 carried by a lever c actuated by the type keys and spacing bar, whereby the drum 6 receives step by step rotary movements in one direction. The adjacent faces of the coaxial spring drums a and b may be toothed as shown in Fig. 1 toprovide a one-way clutch connection. A lever cl actuated by a special key and acting on a collar d on the spindle a serves when, rocked to move the return spring drum 6 out of engagement with the worm wand into engagement with the propelling drum a or vice versa.

The modus operandi of the improved mechanism is as follows 2- In letter spacing, the drums occupy the relative positions indicated in Fig. 1. The drum or is driven in the usual manner while the drum 6 is rotated by the worm and ratchet mechanisms by operation of the lever actuated by the type keys and spacing bars, the spring Z) being tensioned during this period. To return the carriage to the desired position, the lever d is depressed whereby the drums a and b are brought into engagement with the drum 6 moved out of engagement with the worm to whereupon the stronger spring I) overcomes the opposing force of the spring al and returns the carriage to the desired position.

A spring f consisting of a number of plates interposed between the drums a and b and adapted to be overcome on the actuation of the lever d serves normally to maintain the return spring drum in operative relation with the worm w and disengaged from the propelling spring drum a.

The return spring mechanism may be associated with line-spacing mechanism for eftesting line-spacing movements of the platen concomitantly with thereturn mm'ement of the carriage.

What I clalm as my lnvention and desire to secure by Letters Patent is In a, typewriting machine having a spring drum for effecting a forward movement of the carriage, the combination of mechanism for rewinding-said drum inorder to effect a return of the carriage, comprising a second drum-slidably mounted in axial alignment with 1 the first mentioned drum and encnsing a superior spring Wound in the reverse {hr-lotion, a set of projections on' each of the two drums adapted for co-engagement, spring means tending to maintain the second mentioned-drum in a normal position in which the projections are disengaged, an

operating lever adapted to displace the secondmentioned drum into a position in which the tWo sets of projections are in engagement, teeth on the second mentioned drum, a Worm positioned'for engagement With said teeth when the drum is in the normal position but disengaged therefrom When the drum is displaced, ratchet teeth onthe Worm, anda pawl operable by the type keys and spacingbar of the machine and assoeiatei'l Withthe ratchet teethtoefi ect rotation of the worm, whereby. said Worm serves both to Wind up the second mentioneddrum by the eper-ationof the machine-andto prevent its unwindinguntil displaced from-the nerma position.

ALEXANDER J OHN SBHTH. 

